Credit: Eric McCandless/ABC Television Group © 2012 Disney Photo: Grey's Anatomy Season 9, Episode 24: Bailey and Callie

Even though the season finale for Grey's Anatomy Season 10, Episode 24 — is still five weeks away, we're starting to piece together what will happen in the sure-to-be climactic capper.

Casting sides for the episode — cryptic notes about the episode used to cast actors — say that there will be a massive car accident, but we're not so convinced. We think something even worse is going to happen — and that it will be a lot closer to home for the Grey Sloan Memorial docs. Here's our argument:

  • As we know, casting sides can be very cagey, renaming characters and even rewriting storylines. (For example, a casting side for Episode 18 said that the Austrian visitor Dr. Strauss was impressed by a cardiothoracic surgeon, not a neurosurgeon like Derek.)

  • In recent years, the season finales have alternated between disaster drama and and emotional/relationship drama — Season 6 was the hospital shooting, Season 7 was Mer-Der strife, Season 8 was the plane crash, and Season 9 was the Calzona affair. That means that we're due for another disaster here in Season 10.

  • The casting sides mention three possible causes for the "pile-up" scenario: a gang-related carjacking, an out-of-control car, and a wayward dog. Either there's a lot of false information floating around about the accident's cause in the story — or the casting sides writers aren't getting their lies straight!

  • In the sides, a reporter on the scene at Grey Sloan says that it's an "intensely dangerous situation" for her to even be there. If the calamity were a car accident, why would it be dangerous for her to be at the hospital?

  • An eight-month pregnant woman has a tourniqueted arm that is missing part of her forearm and hand. It's not impossible for her to sustain such injuries in a car crash, but they seem more likely to have come from something like a building collapse.

  • TVLine's "May Sweeps Scorecard" notes that one show will have a workplace destroyed during the TV episodes airing in May. Not saying it's Grey's, but not saying it isn't!

  • We've already had a massive car pile-up — in Season 9, Episode 19.

  • Executive producer Tony Phelan tweeted that we'll be "shaken not stirred" by the finale, leading us to infer that some sort of jolt will strike Seattle, whether it be a structure collapse or an earthquake.

What do you think might happen in the finale? Cast your best guess in comments below!

Dan Clarendon is an assistant editor at Wetpaint Entertainment. Follow him on Twitter and Google+!